/*!
 * Ext JS Library 3.1.0
 * Copyright(c) 2006-2009 Ext JS, LLC
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
Ext.ns('Ext.ux.tree');

/**
 * @class Ext.ux.tree.XmlTreeLoader
 * @extends Ext.tree.TreeLoader
 * <p>A TreeLoader that can convert an XML document into a hierarchy of {@link Ext.tree.TreeNode}s.
 * Any text value included as a text node in the XML will be added to the parent node as an attribute
 * called <tt>innerText</tt>.  Also, the tag name of each XML node will be added to the tree node as
 * an attribute called <tt>tagName</tt>.</p>
 * <p>By default, this class expects that your source XML will provide the necessary attributes on each
 * node as expected by the {@link Ext.tree.TreePanel} to display and load properly.  However, you can
 * provide your own custom processing of node attributes by overriding the {@link #processNode} method
 * and modifying the attributes as needed before they are used to create the associated TreeNode.</p>
 * @constructor
 * Creates a new XmlTreeloader.
 * @param {Object} config A config object containing config properties.
 */
Ext.ux.tree.XmlTreeLoader = Ext.extend(Ext.tree.TreeLoader, {
    /**
     * @property  XML_NODE_ELEMENT
     * XML element node (value 1, read-only)
     * @type Number
     */
    XML_NODE_ELEMENT: 1,
    /**
     * @property  XML_NODE_TEXT
     * XML text node (value 3, read-only)
     * @type Number
     */
    XML_NODE_TEXT: 3,

    // private override
    processResponse: function (response, node, callback) {
        var xmlData = response.responseXML;
        var root = xmlData.documentElement || xmlData;

        try {
            node.beginUpdate();
            node.appendChild(this.parseXml(root));
            node.endUpdate();

            if (typeof callback == "function") {
                callback(this, node);
            }
        } catch (e) {
            this.handleFailure(response);
        }
    },

    // private
    parseXml: function (node) {
        var nodes = [];
        Ext.each(node.childNodes, function (n) {
            if (n.nodeType == this.XML_NODE_ELEMENT) {
                var treeNode = this.createNode(n);
                if (n.childNodes.length > 0) {
                    var child = this.parseXml(n);
                    if (typeof child == 'string') {
                        treeNode.attributes.innerText = child;
                    } else {
                        treeNode.appendChild(child);
                    }
                }
                nodes.push(treeNode);
            } else if (n.nodeType == this.XML_NODE_TEXT) {
                var text = n.nodeValue.trim();
                if (text.length > 0) {
                    return nodes = text;
                }
            }
        }, this);

        return nodes;
    },

    // private override
    createNode: function (node) {
        var attr = {
            tagName: node.tagName
        };

        Ext.each(node.attributes, function (a) {
            attr[a.nodeName] = a.nodeValue;
        });

        this.processAttributes(attr);

        return Ext.ux.tree.XmlTreeLoader.superclass.createNode.call(this, attr);
    },

    /*
     * Template method intended to be overridden by subclasses that need to provide
     * custom attribute processing prior to the creation of each TreeNode.  This method
     * will be passed a config object containing existing TreeNode attribute name/value
     * pairs which can be modified as needed directly (no need to return the object).
     */
    processAttributes: Ext.emptyFn
});

//backwards compat
Ext.ux.XmlTreeLoader = Ext.ux.tree.XmlTreeLoader;
